Engine device for work vehicle

ABSTRACT

A engine device for a work vehicle, in which an engine, a first case, and a second case can be constituted in the same vibration structure, and exhaust gas path structure between the engine and the second case can be constituted in such a manner as to reduce costs. The engine device for a work vehicle according to the present invention of the instant application includes the first case for removing particulate matter in exhaust gas of the engine and the second case for removing nitrogen oxides in the exhaust gas of the engine, and configured to connect the first case to the second case via a urea mixing pipe. The engine, the first case, and the second case are integrally adhered, and the engine, the first case, and the second case are configured to be integrally vibrated in a swingable manner.

TECHNICAL FIELD

The present invention of the instant application relates to an enginedevice such as a diesel engine mounted on an agricultural machine (atractor and a combine harvester) or a construction machine (a bulldozer,a hydraulic excavator, and a loader), and more specifically relates toan engine device for work vehicles, in which an exhaust gas purificationdevice is mounted that removes particulate matter (soot andparticulates) included in exhaust gas or nitrogen oxides (NOx) includedin the exhaust gas, and the like.

BACKGROUND OF THE INVENTION

Regarding work vehicles such as a tractor and a wheel loader, anopening/closing fulcrum shaft is arranged in the rear portion of a hoodfor covering an engine, and the hood is rotated about theopening/closing fulcrum shaft, for the purpose of improving theefficiency of maintenance work for the engine arranged in the front of atravelling vehicle body. Also, a technology of purification treatmenthas been known theretofore, wherein a case (hereinafter referred to as“DPF case”) in which a diesel particulate filter is internally provided,and a case (hereinafter referred to as “SCR case”) in which a ureaselective reduction catalyst is internally provided are provided in theexhaust path of a diesel engine as an exhaust gas purification device(exhaust gas after-treatment device), and the exhaust gas is introducedinto the DPF case and the SCR case, thereby purifying the exhaust gasdischarged from the diesel engine (for example, see Patent Literatures 1to 4).

PATENT LITERATURE

-   -   PTL 1: Japanese Unexamined Patent Application Publication No.        2009-74420    -   PTL 2: Japanese Unexamined Patent Application Publication No.        2012-21505    -   PTL 3: Japanese Unexamined Patent Application Publication No.        2013-104394    -   PTL 4: Japanese Unexamined Patent Application Publication No.        2012-177233

SUMMARY OF INVENTION

As Patent Literatures 1 to 3, when the DPF case and the SCR case areassembled while being separated from the engine, the temperature of theexhaust gas supplied from the engine to the DPF case or the SCR case isreduced, which leads to incompletion of regeneration of a dieselparticulate filter or incompletion of chemical reaction such asselective catalyst reduction action. Accordingly, there is a problem inthat a specific device for maintaining the temperature of the exhaustgas in the SCR case at a high degree is required. Also, as PatentLiterature 3, a technology has been disclosed that the DPF case and theSCR case are mounted on two parallel base frames, and the two baseframes are coupled with an object to be installed, thereby mounting theDPF case and the SCR case. However, a mounting surface of the object tobe installed needs to be formed horizontally (flat), and therefore thereis a problem in that it is difficult to support the supporting postureof the DPF case and the SCR case at a predetermined posture due tomachining errors of mounting components such as the base frame.Furthermore, when the diesel particulate filter (soot filter) in the DPFcase is cleaned or replaced, it is necessary to detach the whole of theDPF case, disassemble the DPF case, and then detach the dieselparticulate filter. Accordingly, there is a problem in that cleaningman-hour for the diesel particulate filter cannot be easily reduced.

On the other hand, as Patent Literature 4, when the DPF case and the SCRcase are assembled in the proximity of the engine, reduction intemperature of the exhaust gas supplied from the engine to the SCR caseis alleviated, and the temperature of the exhaust gas in the SCR case iseasily maintained at a high degree, but it is necessary to secureinstallation space for the SCR case on the lateral side of the engine,which causes a problem in that it is difficult to make an engine roomcompact, and the DPF case or the SCR case cannot be supported in acompact way. Also, in a narrow, small engine room, there is a problem inthat assembly workability or maintenance workability of the DPF case,the SCR case, or the like cannot be improved.

Accordingly, it is an object of the present invention of the instantapplication to provide an engine device for a work vehicle, in whichimprovements are provided in the light of the current circumstances.

In order to achieve the object, an engine device for a work vehicle ofthe present invention is such that the engine device may include a firstcase for removing particulate matter in exhaust gas of an engine and asecond case for removing nitrogen oxides in the exhaust gas of theengine, and configured to connect the first case to the second case viaa urea mixing pipe, and wherein the engine, the first case, and thesecond case are integrally adhered, and the engine, the first case, andthe second case are configured to be integrally vibrated in a swingablemanner.

Regarding the engine device for the work vehicle described in the claim1, the present invention is such that a plurality of supporting legbodies are vertically installed in a cylinder head of the engine, and asupporting stand is coupled on an upper end side of the plurality ofsupporting leg bodies, and the first case and the second case areadhered on an upper surface side of the engine via the approximatelyhorizontal supporting stand.

Regarding the engine device for the work vehicle the present inventionis such that an inlet pipe of the first case is arranged on a side wherean exhaust manifold of the engine is installed, and the first case ismounted in such a manner that the exhaust gas in the first case cantransfer in a direction intersecting with a core line of an output shaftof the engine, and the second case is juxtaposed on a lateral part on aninstallation side of the cooling fan of the engine, on a lateral part ofthe first case.

Regarding the engine device for the work vehicle, the present inventionis such that the work vehicle is such that an operating cabin isarranged in rear of a hood in which the engine is internally installed,and a urea water tank for exhaust gas purification is installed betweena front portion of the operating cabin and a rear portion of the engine.

Regarding the engine device for the work vehicle, the present inventionis such that the first case is formed in such a manner as to be dividedinto an exhaust intake side case and an exhaust discharge side case, andthe exhaust discharge side case is configured to be separable in a statewhere the exhaust intake side case is supported on the side of theengine.

Regarding the engine device for the work vehicle, the present inventionis such that the engine device further includes an exhaust outlet pipeconfigured to couple the first case with the urea mixing pipe, and theexhaust outlet pipe is extended on an outer side in a directionintersecting with a transfer direction of the exhaust gas, on an outerside of the exhaust discharge side case, and a coupling portion betweenthe urea mixing pipe and the exhaust outlet pipe is disposed at aposition at a position deviated from separation locus of the exhaustdischarge side case separated in the transfer direction of the exhaustgas.

Regarding the engine device for the work vehicle, the present inventionis such that the engine device further includes a clamping body foradhering the exhaust intake side case and the second case; and aclamping body for adhering the exhaust discharge side case and thesecond case, and it is configured that the first case and the secondcase are integrally adhered with each clamping body, thereby forming anexhaust purification unit.

Regarding the engine device for the work vehicle the present inventionis such that the engine device further includes a clamping body forintegrally adhering the first case and the second case; and a supportingstand for mounting the clamping body, and it is configured that aplurality of supporting leg bodies are vertically installed on an uppersurface side of the engine, and the supporting stand is coupled with anexhaust manifold of the engine and the plurality of supporting legbodies.

According to the present invention, the engine device for the workvehicle includes the first case for removing particulate matter in theexhaust gas of the engine and the second case for removing nitrogenoxides in the exhaust gas of the engine, and configured to connect thefirst case to the second case via the urea mixing pipe, and the engine,the first case, and the second case are integrally adhered, and theengine, the first case, and the second case are configured to beintegrally vibrated in a swingable manner, so that the engine, the firstcase, and the second case can be constituted in the same vibrationstructure, and it is not necessary to apply the vibration-proof couplingto the exhaust path between the engine and the first case and theexhaust path between the first case and the second case, and the exhaustgas path structure between the engine and the second case can heconstituted in such a manner as to reduce costs. That is, it is notnecessary to connect the vibration-proof members, for example, such asthe corrugated flexible pipe or a heat-resistant rubber hose in theexhaust gas path between the first case and the second case, so that theexhaust gas path structure between the engine and the second case can beconstituted in such a manner as to reduce costs.

According to the present invention, the plurality of supporting legbodies are vertically installed in the cylinder head of the engine, andthe supporting stand is coupled on the upper end side of the pluralityof supporting leg bodies, and the first case and the second case areadhered on the upper surface side of the engine via the approximatelyhorizontal supporting stand, so that the supporting stand can be easilyseparated from the accessory components of the engine. Also, the firstcase and the second case are integrally mounted with respect to theengine, thereby simplifying the exhaust gas pipes of each case, and thefirst case and the second case can be adhered with high rigidity to thecylinder head.In addition, the machining errors of the mountingcomponents such as the supporting stand can be alleviated by adjustingthe coupling portions between the plurality of supporting leg bodies andthe supporting stand, and an inclination angle in mounting thesupporting stand can be easily corrected, and the first case and thesecond case can be supported in a predetermined posture. The assemblyworkability, in which the first case and the second case are assembledinto the engine, can be easily improved.

According to the present invention, the inlet pipe of the first case isarranged on the side where the exhaust manifold of the engine isinstalled, and the first case is mounted in such a manner that theexhaust gas in the first case can transfer in the direction intersectingwith the core line of the output shaft of the engine, and the secondcase is juxtaposed on. the lateral part on the installation side of thecooling fan of the engine, on the lateral part of the first case, sothat the first case and the second case are in close vicinity to eachother on the upper surface side of the engine and can be arranged in acompact way, whereas the second case is interposed between the coolingfan and the first case, thereby suppressing the reduction in temperatureof the first case due to the wind from the cooling fan. Also, the ureamixing pipe that supplies the exhaust gas from the first case to thesecond case is supported between the first case and the second case, sothat the second case is interposed between the cooling fan and the ureamixing pipe, and the reduction in temperature of the urea mixing pipedue to the wind from the cooling fan can be suppressed.

According to the present invention, the work vehicle is such that theoperating cabin is arranged in rear of the hood in which the engine isinternally installed, and the urea water tank for exhaust gaspurification is installed between the front portion of the operatingcabin and the rear portion of the engine, so that the, urea water tankcan be heated with the waste heat of the engine and the like, and theurea aqueous solution having a predetermined temperature or higher canbe maintained in the urea water tank, and the reduction in the capacityof the exhaust gas purification of the second case can be prevented incold districts and the like. The water-feeding port of the urea watertank can be adjacently arranged on the operator's boarding and alightingportion of the operating cabin, and water-feeding work of the ureaaqueous solution into the urea water tank can he easily executed at theoperator's boarding and alighting sites, and the workability ofreplenishing the urea aqueous solution for the exhaust gas purificationcan be improved.

According to the present invention, the first case is formed in such amanner as to be divided into the exhaust intake side case and theexhaust discharge side case, and the exhaust discharge side case isconfigured to be separable in a state where the exhaust intake side caseis supported on the side of the engine, so that, during the maintenancework in the interior of the first case, it is not required to remove thewhole of the first case, and the number of detachable components thatnecessitate the maintenance work in the interior of the exhaustdischarge side case (the first case) can be easily reduced, and the sootfilter internally installed in the exhaust discharge side case and thelike can be easily detached, and the cleaning man-hour of the interiorof the exhaust discharge side case or the soot filter, or the like canbe reduced.

According to the present invention, the engine device further includesthe exhaust outlet pipe configured to couple the first case with theurea mixing pipe, and the exhaust outlet pipe is extended on the outerside in the direction intersecting with the transfer direction of theexhaust gas, on the outer side of the exhaust discharge side case, andthe coupling portion between the urea mixing pipe and the exhaust outletpipe is disposed at a position deviated from the separation locus of theexhaust discharge side case separated in the transfer direction of theexhaust gas, so that the fastening bolts of the coupling portion of theurea mixing pipe and the exhaust outlet pipe, or the like are detached,and the coupling of the exhaust intake side case and the exhaustdischarge side case is released, so that the exhaust discharge side caseis slid in the transfer direction of the exhaust gas in the first case,thereby easily separating the exhaust discharge side case from theexhaust intake side case.

According to the present invention, the engine device further includes aclamping body for adhering the exhaust intake side case and the secondcase; and a clamping body for adhering the exhaust discharge side caseand the second case, and it is configured that the first case and thesecond case are integrally adhered with each clamping body, therebyforming an exhaust purification unit, so that the exhaust discharge sidecase can be easily detached by removing the clamping bodies for adheringto the exhaust discharge side case and the second case During themaintenance of the interior of the exhaust discharge side case, theattachment or detachment work of the clamping bodies for adhering to theexhaust intake side case and the second case is eliminated, so thatmaintenance (the cleaning of the soot filter) workability in theinterior of the exhaust discharge side case can be improved.

According to the present invention, the engine device further includes aclamping body for integrally adhering the first case and the secondcase; and a supporting stand for mounting the clamping body, and it isconfigured that a plurality of supporting leg bodies are verticallyinstalled on an upper surface side of the engine, and the supportingstand is coupled with an exhaust manifold of the engine and theplurality of supporting leg bodies, so that the machining errors of themounting components such as the supporting stand can be alleviated byadjusting the coupling portions between the supporting leg bodies andthe supporting stand, and an inclination angle in mounting thesupporting stand can be easily corrected, and the first case and thesecond case can be easily supported in a predetermined posture, and thesupporting stand is separated away from the accessory components of theengine, thereby supporting the first case and the second case in such amanner as to eliminate mutual interference. The assembly workability, inwhich the first case and the second case are assembled into the engine,can be easily improved.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a left side view of a diesel engine illustrating a firstembodiment,

FIG. 2 is a right side view of the diesel engine.

FIG. 3 is a front view of the diesel engine.

FIG. 4 is a rear view of the diesel engine.

FIG. 5 is a plan view of the diesel engine.

FIG. 6 is a perspective front view of the diesel engine.

FIG. 7 is a perspective rear view of the diesel engine.

FIG. 8 is an explanatory bottom view of an exhaust gas purification unitbody.

FIG. 9 is a perspective exploded front view of the exhaust gaspurification unit body.

FIG. 10 is a perspective exploded rear view of the exhaust gaspurification unit body.

FIG. 11 is a perspective exploded right side view of the exhaust gaspurification unit body.

FIG. 12 is a perspective exploded left side view of the exhaust gaspurification unit body.

FIG. 13 is a left side view of a tractor in which the diesel engine ismounted.

FIG. 14 is a plan view of the tractor.

FIG. 15 is a cross-sectional rear view of a supporting stand portion ofthe exhaust gas purification unit body.

FIG. 16 is a cross-sectional rear view of a supporting leg body portionof the exhaust gas purification unit body.

FIG. 17 is a cross-sectional rear view of a case mounting frame bodyportion of the exhaust gas purification unit body.

FIG. 18 is a perspective rear view in which part of a first case isdisassembled.

FIG. 19 is an explanatory view during detachment in which part of thefirst case is disassembled.

Fig. 20 is a side view of a work vehicle in which the diesel engine ismounted.

FIG. 21 is a plan view of the work vehicle.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, a first embodiment, which is an embodiment of the presentinvention, will be described based on drawings (FIGS. 1 to 12). FIG. 1is a left side view of a diesel engine 1 in which an exhaust manifold 6is installed, and FIG. 2 is a right side view of the diesel engine 1 inwhich an intake manifold 3 is installed, and FIG. 3 is a front view ofthe diesel engine 1 in which a cooling fan 24 is installed. It is notedthat the installation side of the exhaust manifold 6 is referred to asthe left lateral surface of the diesel engine 1, and the installationside of the intake manifold 3 is referred to as the right lateralsurface of the diesel engine 1, and the installation side of the coolingfan 24 is referred to as the front surface of the diesel engine 1. Theentire structure of the diesel engine 1 will be described referring toFIGS. 1 to 8.

As illustrated in FIGS. 1 to 7, the intake manifold 3 is arranged on oneside surface of a cylinder head 2 of the diesel engine 1. The cylinderhead 2 is mounted on a cylinder block 5 in which an engine output shaft4 (crankshaft) and pistons (not illustrated) are incorporated. Theexhaust manifold 6 is arranged on the other side surface of the cylinderhead 2. The front end and the rear end of the engine output shaft 4protrude from the front surface and the rear surface of the cylinderblock 5.

As illustrated in FIGS. 1 to 7, a flywheel housing 8 is adhered to therear surface of the cylinder block 5. A flywheel 9 is provided in theflywheel housing 8. The flywheel 9 is pivotably supported on the rearend side of the engine output shaft 4. It is configured such that themotive power of the diesel engine 1 is taken out via the flywheel 9.Furthermore, an oil pan 11 is arranged on the lower surface of thecylinder block 5.

As illustrated in FIGS. 2 to 5 and 7, an exhaust gas recirculationdevice (EGR) 15 that takes in the exhaust gas for recirculation isarranged on the intake manifold 3. An air cleaner 16 (see FIG. 13) isconnected to the intake manifold 3. It is configured such that outsideair that is purified by removing dust by means of the air cleaner 16 isdelivered to the intake manifold 3 and supplied to each cylinder of thediesel engine 1.

With the aforementioned constitution, part of the exhaust gas dischargedfrom the diesel engine 1 to the exhaust manifold 6 is recirculated fromthe intake manifold 3 into each cylinder of the diesel engine 1 via theexhaust gas recirculation device 15, thereby reducing the combustiontemperature of the diesel engine 1, reducing the emissions of nitrogenoxides (NOx) from the diesel engine 1, and improving the fuelconsumption of the diesel engine 1.

It is noted that a coolant pump 21 for circulating a coolant to thecylinder block 5 and a radiator 19 (see FIG. 13) is provided. Thecoolant pump 21 is arranged on the installation side of the cooling fan24 of the diesel engine 1. The coolant pump 21 and the cooling fan 24are coupled with the engine output shaft 4 via a V belt 22 and the like,thereby driving the coolant pump 21 and the cooling fan 24. It isconfigured such that the coolant is delivered from the coolant pump 21into the cylinder block 5 via an EGR cooler 18 of the exhaust gasrecirculation device 15, while the diesel engine 1 is cooled by the windof the cooling fan 24.

As illustrated in FIGS. 1 to 8, the diesel engine 1 includes a firstcase 28 as a diesel particulate filter (DPF) that removes particulatematter in the exhaust gas of the diesel engine 1 and a second case 29 asa urea selective catalyst reduction (SCR) system that removes thenitrogen oxides in the exhaust gas of the diesel engine 1, as an exhaustgas purification device 27 for purifying the exhaust gas discharged fromeach cylinder of the diesel engine 1. As illustrated in FIGS. 1 and 2,an oxidation catalyst 30 and a soot filter 31 are internally provided inthe first case 28 as a DPF case. An SCR catalyst 32 and an oxidationcatalyst 33 for urea selective catalyst reduction are internallyprovided in the second case 29 as an SCR case.

The exhaust gas discharged from each cylinder of the diesel engine 1 tothe exhaust manifold 6 is released to the outside via the exhaust gaspurification device 27 and the like. It is configured such that carbonmonoxide (CO), hydrocarbon (HC), particulate matter (PM), and nitrogenoxides (NOx) in the exhaust gas of the diesel engine 1 are reduced bymeans of the exhaust gas purification device 27.

The first case 28 and the second case 29 are constituted in a lateral,oblong cylindrical shape elongated in the orthogonal directionintersecting with the output shaft (crankshaft) 4 of the diesel engine 1when viewed from a plane (see FIGS. 3 to 5). A DPF inlet pipe 34 thattakes in the exhaust gas and a DPF outlet pipe 35 that discharges theexhaust gas are provided on the cylindrical bilateral sides (one endside and the other end side of the transfer direction of the exhaustgas) of the first case 28. Similarly, an SCR inlet pipe 36 that takes inthe exhaust gas and an SCR outlet pipe 37 that discharges the exhaustgas are provided on the bilateral sides (one end side and the other endside of the transfer direction of the exhaust gas) of the second case29.

Also, a supercharger 38 that forcibly feeds air into the diesel engine1, and an exhaust gas outlet pipe 7 fastened with bolts to the exhaustmanifold 6 are arranged at the exhaust gas outlet of the exhaustmanifold 6. It is configured such that the DPF inlet pipe 34communicates with the exhaust manifold 6 via the supercharger 38 and theexhaust gas outlet pipe 7, and the exhaust gas of the diesel engine 1 isintroduced into the first case 28, while the SCR inlet pipe 36 isconnected to the DPF outlet pipe 35 via a urea mixing pipe 39, and theexhaust gas of the first case 28 is introduced into the second case 29.In addition, the DPF outlet pipe 35 and the urea mixing pipe 39 aredetachably connected by fastening with bolts on a DPF outlet-side flangebody 41. It is noted that the SCR inlet pipe 36 and the urea mixing pipe39 are detachably connected on an SCR inlet-side flange body 40.

As illustrated in FIG. 2, a fuel pump 42 and a common rail 43 that areconnected to a fuel tank 45 illustrated in FIG. 13 (FIG. 14) areprovided in respective injectors (not illustrated) corresponding to themulti cylinders of the diesel engine 1. The common rail 43 and a fuelfilter 44 are arranged on the installation side of the intake manifold 3of the cylinder head 2, and the fuel pump 42 is arranged in the cylinderblock 5 below the intake manifold 3. It is noted that each injectorincludes a fuel injection valve (not illustrated) of an electromagneticopening/closing control type.

The fuel in the fuel tank 45 is drawn in by the fuel pump 42 via thefuel filter 44, while the common rail 43 is connected to the dischargeside of the fuel pump 42, and the cylindrical common rail 43 isconnected to each injector of the diesel engine 1. It is noted thatsurplus fuel, out of the fuel that is pressure-fed from the fuel pump 42to the common rail 43, is returned to the fuel tank 45, and thehigh-pressure fuel is temporarily retained in the common rail 43, andthe high-pressure fuel in the common rail 43 is supplied into theinterior of each cylinder (cylinder) of the diesel engine 1.

With the aforementioned constitution, the fuel in the fuel tank 45 ispressured-fed to the common rail 43 by means of the fuel pump 42, andthe high-pressure fuel is stored in the common rail 43, and the fuelinjection valves of the injectors are respectively controlled in anopenable/closable manner, thereby injecting the high-pressure fuel inthe common rail 43 into the injectors of the diesel engine 1. That is,the fuel injection valve of each injector is electronically controlled,so that the injection pressure, injection time, and injection period(injection amount) of the fuel can be controlled with high accuracy.Accordingly, the nitride oxides (NOx) discharged from the diesel engine1 can be reduced.

Next, a tractor 51 on which the diesel engine 1 is mounted will bedescribed referring to FIGS. 13 and 14. The tractor 51 as a work vehicleillustrated in FIGS. 13 and 14 is configured to be equipped with atilling machine not illustrated and perform tillage so as to till farmfields. FIG. 13 is a side view of a tractor for farm work, and FIG. 14is a plan view of the tractor. It is noted that, in the descriptionbelow, a left side with respect to the advance direction of the tractoris merely referred to as “left side”, and a right side with respect tothe advance direction of the tractor is merely referred to as “rightside”.

As illustrated in FIGS. 13 and 14, the tractor 51 for farm work as awork vehicle is configured such that a travelling vehicle body 52 issupported by a pair of right and left front wheels 53 and a pair ofright and left rear wheels 54, and the diesel engine 1 is mounted on thefront portion of the travelling vehicle body 52, and the front wheels 53and the rear wheels 54 are driven by the diesel engine 1, which allowsthe tractor 51 to travel forward and backward. The upper surface sideand the right and left lateral surface sides of the diesel engine 1 arecovered by an openable/closable hood 56.

Also, a cabin 57 that an operator rides on is installed in the rear ofthe hood 56 on the upper surface of the travelling vehicle body 52. Amaneuvering seat 58 that the operator takes, and maneuvering instrumentssuch as a maneuvering handle 59 as a steering means are provided in theinterior of the cabin 57. Also, a pair of right and left steps 60 thatthe operator ascends or descends are provided on the right and leftexternal lateral sections of the cabin 57, and the fuel tank 45 forsupplying the fuel to the diesel engine 1 is provided on the inner sideof the steps 60 and on the lower side with respect to the bottom portionof the cabin 57.

Also, the travelling vehicle body 52 includes a mission case 61 forshifting the output from the diesel engine 1 and transmitting the outputto the rear wheels 54 (front wheels 53). The tilling machine notillustrated or the like is coupled with the rear portion of the missioncase 61 in such a manner as to be capable of being hoisted and loweredvia a lower link 62, a top link 63, a lift arm 64, and the like.Furthermore, a PTO shaft 65 for driving the tilling machine and the likeis provided on the rear lateral surface of the mission case 61. It isnoted that the travelling vehicle body 52 of the tractor 51 isconstituted by the diesel engine 1, the mission case 61, and a clutchcase 66 that couples the diesel engine 1 with the mission case 61.

Furthermore, the mounting structure of the first case 28 and the secondcase 29 will be described referring to FIGS. 1 to 12 and 15 to 17. Asillustrated in FIGS. 9 to 12 and 15 to 17, a front portion supportingleg body 82 that fastens a lower end side with bolts 81 to a right sidecorner section on the front surface of the cylinder head 2, a lateralportion supporting leg body 84 that fastens a lower end side with bolts83 to a front side corner section on the left side surface of thecylinder head 2, and a rear portion supporting leg body 86 that fastensa lower end side with bolts 85 to a rear surface of the cylinder head 2are included, and each of the supporting leg bodies 82, 84, and 86 isvertically installed in the cylinder head 2. A rectangular supportingstand 87 formed by sheet metal working is included, and the lateralsurface and the upper surface side of the supporting stand 87 arefastened with bolts 88 to the upper end side of the supporting legbodies 82, 84, and 86. Also, a tabular positioning body 89 is welded andfixed on the upper surface of the supporting stand 87 installed oppositeto the exhaust gas outlet pipe 7, and part of the tabular lower surfaceof the positioning body 89 is brought in surface contact with part of aflat exhaust gas outlet surface 7 a of the exhaust gas outlet pipe 7opened upwardly, and the positioning body 89 is fastened with bolts 90to the exhaust gas outlet pipe 7. It is configured that the surfacecontact of the positioning body 89 with the exhaust gas outlet pipe 7allows the upper surface of the supporting stand 87 to be approximatelyhorizontal to the diesel engine 1.

As illustrated in FIGS. 11 and 12, and 15 to 17, a pair of left casefixing body 95 and right case fixing body 96, and four fastening bands97 are included as a clamping body for arranging the first case 28 andthe second case 29 in parallel. The first case 28 is adhered with theright and left fastening bands 97 to rear side placement portions of theleft case fixing body 95 and the right case fixing body 96, and thesecond case 29 is adhered with the right and left fastening bands 97 tofront side placement portions of the left case fixing body 95 and theright case fixing body 96. Accordingly, the first case 28 and the secondcase 29, each of which is formed in an oblong cylindrical shapeelongated in the right-and-left direction, are arranged in parallel tothe upper surface side of the diesel engine 1, so that the first case 28is positioned on the rear side of the upper surface of the diesel engine1, and the second case 29 is positioned on the front side of the uppersurface of the diesel engine 1.

As illustrated in FIGS. 9 to 12, and 17, as an exhaust gas purificationunit, the exhaust gas purification device 27 is configured such that afront and back supporting frame bodies 98 are fastened with bolts 99 tothe front-and-back end portions of the left case fixing body 95 and theright case fixing body 96 in such a manner that a mounting position(supporting posture) can be adjusted, and the left case fixing body 95and the right case fixing body 96 and the front and back supportingframe bodies 98 are coupled in a rectangular frame shape, and the firstcase 28 and the second case 29 are adhered to the left case fixing body95, the right case fixing body 96, and the front and back supportingframe bodies 98 via the right and left fastening bands 97. It is notedthat the internal diameter size of the bolt through-hole of the frontand back supporting frame bodies 98 is formed larger, compared with theexternal diameter size of the bolts 99, and the bolts 99 are insertedinto the bolt through-holes of the front and back supporting framebodies 98 in a freely fittable manner, and it is configured that whenthe case fixing bodies 95 and 96 are adhered to the front and backsupporting frame bodies 98, while the coupling posture of the front andback supporting frame bodies 98 with respect to the case fixing bodies95 and 96 is supported in a predetermined posture, the case fixingbodies 95 and 96 are threadedly engaged with the bolts 99, and thesupporting frame bodies 98 are fastened with the bolts 99 to the casefixing bodies 95 and 96.

Also, right and left hanging members 91 are fastened with bolts 92 tothe front end side of the left case fixing body 95 and the rear end sideof the right case fixing body 96, and the right and left hanging members91 are arranged at diagonal positions of a rectangular frame of the casefixing bodies 95 and 96 and the front and back supporting frame bodies98. In contrast, front and rear temporal fixing bolt bodies 93 arevertically installed on the upper surface of the supporting stand 87disposed approximately horizontally, and the front and rear temporalfixing bolt bodies 93 are arranged at diagonal arrangements of the rightand left hanging members 91 and at diagonal positions on the oppositeside. That is, the right and left hanging members 91 and the front andrear temporal fixing bolt bodies 93 are allocated and arranged atvertical angle portions of the rectangular frame of the case fixingbodies 95 and 96 and the front and back supporting frame bodies 98.

Next, the assembly procedure of assembling the exhaust gas purificationdevice 27 (the exhaust purification unit) in the diesel engine 1 will bedescribed. As illustrated in FIGS. 9 to 12, first, in assembling theexhaust gas purification device (the exhaust purification unit) 27, apair of supporting frame bodies 98 made of sheet metal, whose endsurface is formed in an L shape, are fastened with the bolts 99 to bothend portions of the left case fixing body (clamping body) 95 and theright case fixing body (clamping body) 96. When the bolts 99 aretightened, looseness between the bolt hole of each supporting frame body98 and the bolt 99 is utilized in such a manner that the height of theupper surface of the left case fixing body 95 is flush with the heightof the upper surface of the right case fixing body 96, and the bolts 99are tightened while the coupling positions of the case fixing bodies 95and 96 and the supporting frame bodies 98 are adjusted, and the casefixing bodies 95 and 96 and the supporting frame bodies 98 are coupledin a rectangular frame shape.

Subsequently, the first case 28 and the second case 29 are placed in apredetermined direction (parallel) on upward-directed concave supportingportions on the upper surface side of the case fixing bodies 95 and 96,and the DPF outlet-side flange body 41 is fastened with bolts to the DPFoutlet pipe 35, and other end side of the urea mixing pipe 39 isfastened with bolts to the SCR inlet pipe 36 via the SCR inlet-sideflange body 40, and the first case 28, the second case 29, and the ureamixing pipe 39 are integrally combined. Then, two fastening bands 97 arerespectively mounted in a half wound form on each upper surface side ofthe first case 28 and the second case 29, and the lower end side of eachfastening band 97 is fastened with bolts to each of the case fixingbodies 95 and 96, and the hanging members 91 are fastened with the bolts92 to each of the case fixing bodies 95 and 96, thereby completing theassembly of the exhaust gas purification device 27. It is noted thatwhen the SCR inlet-side flange body 40 is fastened with bolts, a sensorbracket 112 is also fastened with bolts to the SCR inlet-side flangebody 40, and a differential pressure sensor 111 is mounted on the sensorbracket 112.

On the other hand, in the neighborhood of a final assembly process of anassembly line (engine assembly site) of the diesel engine 1, respectivelower end sides of the front portion supporting leg body 82, the lateralportion supporting leg body 84, and the rear portion supporting leg body86 are fastened with the bolts 81, 83, and 85 to the cylinder head 2 ofthe diesel engine 1 for which the assembly work is approximatelycompleted, and each of the supporting leg bodies 82, 84, and 86 isvertically installed in the cylinder head 2. Subsequently, thesupporting stand 87 is placed on the upper end side of each of thesupporting leg bodies 82, 84, and 86, and the lower surface of thepositioning body 89 is brought in surface contact with the exhaust gasoutlet surface 7 a of the exhaust gas outlet pipe 7, and the supportingstand 87 is fastened with the bolts 88 to each of the supporting legbodies 82, 84, and 86 in a state where the upper surface of thesupporting stand 87 is supported approximately horizontally, and thesupporting stand 87 is fixed in a horizontal posture on the uppersurface side of the diesel engine 1.

Furthermore, at a work site in the neighborhood of the final assemblyprocess of the diesel engine 1, the exhaust gas purification device 27,for which the assembly is completed as described above, is suspended ona loading-and-unloading device (hoist or chain block) not illustratedvia the hanging members 91 and transferred to the upper surface side ofthe diesel engine 1 in which the supporting stand 87 is assembled asdescribed above, and the front and back supporting frame bodies 98 areplaced from the upper side on the approximately horizontal upper surfaceof the supporting stand 87 via the front and rear temporal fixing boltbodies 93, and the front and back supporting frame bodies 98 arefastened with bolts 100 to the supporting stand 87, and the exhaust gaspurification device 27 (the first case 28 and the second case 29) isunited on the upper surface side of the diesel engine 1, therebycompleting the assembly work in which the exhaust gas purificationdevice 27 is assembled into the diesel engine 1.

Also, the urea mixing pipe 39 is arranged between the first case 28 andthe second case 29, in parallel to the first case 28 and the second case29. The first case 28, the second case 29, and the urea mixing pipe 39are supported at a high position with respect to the cooling air path(shroud 101 illustrated in FIG. 1) of the cooling fan 24 via the uppersurface of the supporting stand 87, and the front side of the ureamixing pipe 39 is blocked with the second case 29. Urea water suppliedin the urea mixing pipe 39 is prevented from being crystallized, whichis attributed to the reduction of the exhaust gas temperature in theurea mixing pipe 39 that is caused by the cooling wind of the coolingfan 24. Also, it is configured such that the urea water supplied in theurea mixing pipe 39 is mixed into the exhaust gas leading from the firstcase 28 to the second case 29 as ammonia.

As illustrated in FIGS. 1 to 12, regarding the engine device for thework vehicle that includes the first case 28 that removes theparticulate matter in the exhaust gas of the diesel engine 1 and thesecond case 29 that removes the nitrogen oxides in the exhaust gas ofthe diesel engine 1 and connects the first case 28 to the second case 29via the urea mixing pipe 39, the engine device includes the case fixingbodies 95 and 96 for adhering to the first case 28 and the second case29, and the hanging members 91 are adhered to the case fixing bodies 95and 96. Accordingly, in a state where the first case 28 and the secondcase 29 are integrally assembled by means of the case fixing bodies 95and 96 as the exhaust gas purification device (the exhaust purificationunit) 27, the exhaust purification unit 27 can be hanged and supportedby the loading-and-unloading device and the like via the hanging members91. Regarding the assembly and disassembly work in which the exhaust gaspurification device 27 is attached or detached on the upper surface sideof the diesel engine 1, the exhaust gas purification device 27, which isa heavy weight component, can be easily handled.

As illustrated in FIGS. 1 to 12, the urea mixing pipe 39 is coupledbetween the first case 28 and the second case 29 that are integrallyadhered by means of the case fixing bodies 95 and 96, thereby formingthe exhaust gas purification device 27 as the exhaust purification unit,and a pair of hanging members 91 are arranged in such a manner as toface each other on the outer circumferential side of the diagonalposition in a plane view, out of the outer circumferential side of theexhaust gas purification device 27. Accordingly, in the neighborhood ofthe final assembly process in the assembly process of the diesel engine1, the exhaust gas purification device 27 can be easily assembled intothe diesel engine 1, and the exhaust gas purification device 27 can beeasily detached from the diesel engine 1 during maintenance work, repairwork of the diesel engine 1, or the like.

As illustrated in FIGS. 1 to 12, the lower surface side of thesupporting stand 87 is coupled with the upper surface side of the dieselengine 1 via the plurality of supporting leg bodies 82, 84, and 86, andthe supporting stand 87 is arranged on the upper surface side of thediesel engine 1, and the case fixing bodies 95 and 96 are adhered to theapproximately horizontal upper surface side of the supporting stand 87in a detachable manner. Accordingly, while interference with accessorycomponents and the like on the upper surface side of the diesel engine 1can be easily reduced, the assembly workability of the diesel engine 1or the maintenance workability of the diesel engine 1 can be easilyimproved.

As illustrated in FIGS. 1 to 12, regarding structure in which thecooling fan 24 is provided on one side of the diesel engine 1, theheight of the approximately horizontal upper surface of the supportingstand 87 is formed higher than the height of the upper portion of thecooling fan 24. Accordingly, the wind from the cooling fan 24 istransferred to the lower surface side of the supporting stand 87,thereby appropriately maintaining the air cooling efficiency of thediesel engine 1, and further the temperature of the exhaust gaspurification device 27 as the exhaust purification unit can be preventedfrom reducing due to the wind from the cooling fan 24, and the exhaustgas purification device 27 is kept at a predetermined temperature orhigher, thereby improving the efficiency of exhaust purification.

As illustrated in FIGS. 1 to 12, regarding the engine device for thework vehicle that includes the first case 28 that removes theparticulate matter in the exhaust gas of the diesel engine 1 and thesecond case 29 that removes the nitrogen oxides in the exhaust gas ofthe diesel engine 1 and connects the first case 28 to the second case 29via the urea mixing pipe 39, the first case 28 and the second case 29are integrally adhered by means of the case fixing bodies 95 and 96, thefastening bands 97, and the supporting frame bodies 98 as the clampingmeans, thereby forming the exhaust purification unit 27, and it isconfigured that the exhaust gas purification device 27 as the exhaustpurification unit is detachably supported in the diesel engine via thecase fixing bodies 95 and 96, the fastening bands 97, and the supportingframe bodies 98. Accordingly, the diesel engine 1 and the exhaust gaspurification device 27 can be integrally constituted in same vibrationstructure, which eliminates the vibration-proof coupling for the exhaustlinking portions of the first case 28 and the second case 29, and thelike, and the exhaust gas discharging paths in the diesel engine 1 andthe exhaust gas purification device 27 are configured to reduce costs.Also, the exhaust gas purification device 27 is assembled in advance ata site that is different from the assembly work site of the dieselengine 1, and the exhaust gas purification device 27 can be placed onthe diesel engine 1 in the neighborhood of the final process in theassembly work of the diesel engine 1, thereby improving the assemblyworkability of the diesel engine 1.

As illustrated in FIGS. 1 to 12, it is configured that the supportingstand 87 is approximately horizontally adhered on the upper surface sideof the diesel engine 1, and the case fixing bodies 95 and 96 are adheredon the upper surface side of the supporting stand 87 via the supportingframe bodies 98, and the first case 28 and the second case 29 aresupported in a sideways posture on the upper surface side of the dieselengine 1 via the case fixing bodies 95 and 96 and the fastening bands97, and the urea mixing pipe 39 is supported between the first case 28and the second case 29 on the upper surface side of the first case 28and the second case 29. Accordingly, the exhaust gas purification device27 can be easily assembled and disassembled according to the combinationand separation of the supporting stand 87 and the supporting framebodies 98, and the first case 28 and the second case 29 can be reducedin bulk and supported so as to be compact in size on the upper surfaceside of the diesel engine 1. Also, a mounting interval between the firstcase 28 and the second case 29 can be maintained constant via the casefixing bodies 95 and 96 and the fastening bands 97, and exhaust gas pipestructure such as the urea mixing pipe 39 between the cases 28 and 29can be simplified.

As illustrated in FIGS. 9 to 12, it is configured that the lower endside of the plurality of supporting leg bodies 82, 84, and 86 is adheredto the outer circumferential surface of the cylinder head 2 of thediesel engine 1, and the approximately horizontal supporting stand 87 isdetachably coupled on the upper end side of the plurality of supportingleg bodies 82, 84, and 86, and the exhaust gas purification device 27 isplaced on the upper surface side of the diesel engine 1 via thesupporting stand 87. Accordingly, the coupling portions of the pluralityof supporting leg bodies 82, 84 and 86 and the supporting stand 87 areattached and detached, and the supporting stand 87 is removed, and theupper surface side of the diesel engine 1 is opened wide, andmaintenance work on the upper surface side of the diesel engine 1 can beeasily executed, and the supporting stand 87 can be firmly coupled withthe cylinder head 2 via the plurality of supporting leg bodies 82, 84,and 86, and the exhaust gas purification device 27 can be supported withhigh rigidity on the upper surface side of the diesel engine 1.

As illustrated in FIGS. 1 to 7, it is configured that the exhaust gaspurification device 27 is supported within a width of the diesel engine1 in the core-line direction of the output shalt 4 via the supportingstand 87, and the direction intersecting with the core line of theoutput shaft 4 of the diesel engine 1 corresponds to the transferdirection of the exhaust gas in the first case 28 or the second case 29.Accordingly, the exhaust gas inlet of the first case 28 is directed onthe side of the exhaust manifold 6 of the diesel engine 1, so that theexhaust gas purification device 27 can be supported in a posture inwhich the exhaust gas outlet of the second case 29 is directed on theside of the intake manifold 3 of the diesel engine 1. The exhaust gaspath leading from the exhaust manifold 6 of the diesel engine 1 to theexhaust gas outlet of the second case 29 can be formed in such a manneras to be shortened, and the exhaust gas purification device 27 can beplaced in a compact way on the upper surface side of the diesel engine1.

On the other hand, as illustrated in FIGS. 13 and 14, with respect tothe front surface of the cabin 57, a tailpipe 78 is vertically installedon the front surface of the corner section on the right side of thecabin 57, and the lower end side of the tailpipe 78 is extended to theinterior of the hood 56, and the lower end side of the tailpipe 78 isconnected to the SCR outlet pipe 37 via a corrugated-pipe-shapedflexible pipe 79, and the exhaust gas purified in the second case 29 isdischarged from the tailpipe 78 to the upward direction of the cabin 57.Mechanical vibration transmitted from the side of the diesel engine 1 tothe side of the tailpipe 78 is reduced according to the connection ofthe flexible pipe 79. Also, with respect to the front surface of thecabin 57, a urea water tank 71 is installed on the left side portion ofthe hood 56 on the side opposite to the right side portion where thetailpipe 78 is arranged. That is, the tailpipe 78 is arranged at theright side portion of the rear portion of hood 56, whereas the ureawater tank 71 is allocated and arranged at the left side portion of therear portion of the hood 56. It is noted that, as illustrated by avirtual line in FIGS. 13 and 14, in the structure in which the tailpipe78 a for adhering to the side of the diesel engine 1 is included, thetailpipe 78 is integrally coupled with the SCR outlet pipe 37, therebyomitting the flexible pipe 79.

Furthermore, the urea water tank 71 is mounted on the travelling vehiclebody 52 (the bottom portion frame of the cabin 57 and the like) of therear portion on the left side of the hood 56. An oil-feeding port 46 ofthe fuel tank 45 and a water-feeding port 72 of the urea water tank 71are adjacently provided on the front-surface lower portion on the leftside of the cabin 57. The tailpipe 78 is arranged on the front surfaceon the right side of the cabin 57, on which the operator is less likelyto get on/off, while the oil-feeding port 46 and the water-feeding port72 are arranged on the front surface on the left side of the cabin 57,on which the operator is more likely to get on/off. It is noted that thecabin 57 is configured in such a manner that the operator can take orleave the maneuvering seat 58 from any of the right side or the leftside.

Also, as illustrated in FIGS. 3 to 5, and 14, a urea water injectionpump 73 that pressure-feeds the urea aqueous solution in the urea watertank 71, an electric motor 74 that drives the urea water injection pump73, and a urea water injection nozzle 76 that connects the urea waterinjection pump 73 via a urea water injection pipe 75 are included. Theurea water injection nozzle 76 is mounted on the urea mixing pipe 39 viaan injection pedestal 77, and the urea aqueous solution is sprayed fromthe urea water injection nozzle 76 into the interior of the urea mixingpipe 39.

With the aforementioned constitution, carbon monoxide (CO) orhydrocarbon (HC) in the exhaust gas from the engine 1 is reduced by theoxidation catalyst 30 and the soot filter 31 in the first case 28.Subsequently, the urea water from the urea water injection nozzle 76 ismixed with the exhaust gas from the diesel engine 1 in the interior ofthe urea mixing pipe 39. Then, the nitrogen oxides (NOx) in the exhaustgas mixed with the urea water as ammonia is reduced by the SCR catalyst32 and the oxidation catalyst 33 in the second case 29 and dischargedfrom the tailpipe 78 to the outside.

As illustrated in FIGS. 1 to 12, and 15, regarding the engine device forthe work vehicle that includes the first case 28 that removes theparticulate matter in the exhaust gas of the diesel engine 1 and thesecond case 29 that removes the nitrogen oxides in the exhaust gas ofthe diesel engine 1 and connects the first case 28 to the second case 29via the urea mixing pipe 39, the engine device includes the supportingleg bodies 82, 84, and 86 that are installed in such a manner as toprotrude from the diesel engine 1, and the supporting stand 87 adheredto the supporting leg bodies 82, 84, and 86, and it is configured thatthe first case 28 and the second case 29 are mounted on the planesurface of the supporting stand 87. Accordingly, the supporting stand 87can be easily adhered to the diesel engine 1 via the supporting legbodies 82, 84, and 86 in a retrofitting work (in the neighborhood of thefinal assembly process of the diesel engine 1), and the first case 28and the second case 29 can be supported in an appropriate posture on thesupporting stand 87 of the diesel engine 1, and the attachable anddetachable workability of the first case 28 and the second case 29 canbe improved.

As illustrated in FIGS. 1 to 12, and 15, with respect to the outer sidesurface of the diesel engine 1, the plane surface of the supportingstand 87 (the bottom surface of the positioning body 89) is brought insurface contact with the horizontal surface (the exhaust gas outletsurface 7 a) of the exhaust gas outlet portion (the exhaust gas outletpipe 7), and the supporting stand 87 is joined with the outer sidesurface of the diesel engine 1 via the horizontal surface (the exhaustgas outlet surface 7 a) on the outside of the diesel engine 1 and theplane surface of the supporting stand 87 (the bottom surface of thepositioning body 89), and it is configured that when the supportingstand 87 is fixed on the supporting leg bodies 82, 84, and 86, the uppersurface side of the supporting stand 87 is disposed approximatelyhorizontally. Accordingly, while a mounting angle of the supportingstand 87 can be easily determined with the coupling between the exhaustgas outlet pipe 7 (the exhaust gas outlet portion) and the supportingstand 87, the supporting stand 87 is constituted in metal sheetstructure having high rigidity, thereby easily securing the mountingintensity. For example, the assembly workability, for which the mountingangle of the supporting stand 87 with respect to the diesel engine 1 ishorizontally formed, and the like can be improved.

As illustrated in FIGS. 1 to 12, and 15, it is configured that thepositioning body 89 is integrally adhered to the supporting stand 87,and the positioning body 89 is brought in surface contact with theopening surface (the exhaust gas outlet surface 7 a) of the exhaust gasoutlet portion (the exhaust gas outlet pipe 7) of the diesel engine 1,and the supporting stand 87 is joined with the side of the diesel engine1 via the positioning body 89, and the upper surface side of thesupporting stand 87 is disposed approximately horizontally. Accordingly,after the supporting stand 87 is formed by press work or the like, thesupporting stand 87 and the positioning body 89 are coupled with weldingwork or the like, and the lower surface of the positioning body 89 canbe formed in parallel to the upper surface of the supporting stand 87with high precision. The upper surface side of the supporting stand 87can be formed approximately horizontally with the surface contactbetween the side of the diesel engine 1 and the positioning body 89,without preparing a specific coupling jig for the supporting stand 87.The positioning body 89 is provided as the coupling jig for thesupporting stand 87, so that the attachment and detachment work of thesupporting stand 87 can be easily executed at a repairing site of thediesel engine 1 and the like, where the coupling jig for the supportingstand 87 has not been prepared.

As illustrated in FIGS. 1 to 12, and 15, regarding the structure inwhich the first case 28 and the second case 29 are integrallyconstituted as the exhaust purification unit (the exhaust gaspurification device 27), it is configured that the exhaust purificationunit (the exhaust gas purification device 27) is integrally attached ordetached on the flat upper surface side of the supporting stand 87 whoselower surface side is adhered to the supporting leg bodies 82, 84, and86. Accordingly, the first case 28 and the second case 29 can beattached or detached as a single component, and the assembly anddisassembly workability of the first case 28 and the second case 29, themaintenance workability of the diesel engine 1, or the like can beimproved.

As illustrated in FIGS. 1 to 8, regarding the engine device for the workvehicle that includes the first case 28 that removes the particulatematter in the exhaust gas of the diesel engine 1 and the second case 29that removes the nitrogen oxides in the exhaust gas of the diesel engine1 and connects the first case 28 to the second case 29 via the ureamixing pipe 39, the diesel engine 1, the first case 28, and the secondcase 29 are integrally adhered, and the diesel engine 1, the first case28, and the second case 29 are integrally constituted in a swingablemanner. Accordingly, the diesel engine 1, the first case 28, and thesecond case 29 can be constituted in the same vibration structure, andit is not necessary to apply the vibration-proof coupling to the exhaustpath between the diesel engine 1 and the first case 28 and the exhaustpath between the first case 28 and the second case 29, so that theexhaust gas path structure between the diesel engine 1 and the secondcase 29 can be constituted in such a manner as to reduce costs. That is,it is not necessary to connect the vibration-proof members, for example,such as the corrugated flexible pipe or a heat-resistant rubber hose inthe exhaust gas path between the first case 28 and the second case 29,so that the exhaust gas path structure between the diesel engine 1 andthe second case 29 can be constituted in such a manner as to reducecosts.

As illustrated in FIGS. 1 to 10, the plurality of supporting leg bodies82, 84, and 86 are vertically installed in the cylinder head 2 of thediesel engine 1, and the supporting stand 87 is coupled with the upperend sides of the plurality of supporting leg bodies 82, 84, and 86, andthe first case 28 and the second case 29 are adhered on the uppersurface side of the diesel engine 1 via the approximately horizontalsupporting stand 87. Accordingly, the supporting stand 87 can be easilyseparated from the accessory components of the diesel engine 1. Also,the first case 28 and the second case 29 are integrally mounted withrespect to the diesel engine 1, thereby simplifying the exhaust gaspipes of the cases 28 and 29, and the first case 28 and the second case29 can be adhered with high rigidity to the cylinder head 2. Inaddition, the machining errors of the mounting components such as thesupporting stand 87 can be alleviated by adjusting the coupling portionsbetween the plurality of supporting leg bodies 82, 84, and 86 and thesupporting stand 87, and an inclination angle in mounting the supportingstand 87 can be easily corrected, and the first case 28 and the secondcase 29 can be supported in a predetermined posture. The assemblyworkability, in which the first case 28 and the second case 29 areassembled into the diesel engine 1, can be easily improved.

As illustrated in FIGS. 1 to 8, the DPF inlet pipe 34 of the first case28 is arranged on the side where the exhaust manifold 6 of the dieselengine 1 is installed, and the first case 28 is mounted in such a mannerthat the exhaust gas in the first case 28 can be transferred in thedirection intersecting with the core line of the output shaft of thediesel engine 1, and the second case 29 is juxtaposed on the lateralsection on the installation side of the cooling fan 24 of the dieselengine 1 on the lateral section of the first case 28. Accordingly, thefirst case 28 and the second case 29 are in close vicinity to each otheron the upper surface side of the diesel engine 1 and can be arranged ina compact way, whereas the second case 29 is interposed between thecooling fan 24 and the first case 28, thereby suppressing the reductionin temperature of the first case 28 due to the wind from the cooling fan24. Also, the urea mixing pipe 39 that supplies the exhaust gas from thefirst case 28 to the second case 29 is supported between the first case28 and the second case 29, so that the second case 29 is interposedbetween the cooling fan 24 and the urea mixing pipe 39, and thereduction in temperature of the urea mixing pipe 39 due to the wind fromthe cooling fan 24 can be suppressed.

As illustrated in FIGS. 1 to 8, 13, and 14, regarding the work vehiclein which the operating cabin 57 is arranged in rear of the hood 56 inwhich the diesel engine 1 is internally installed, the urea water tank71 for exhaust gas purification is installed between the front portionof the operating cabin 57 and the rear portion of the diesel engine 1.Accordingly, the urea water tank 71 can be heated with the waste heat ofthe diesel engine 1 and the like, and the urea aqueous solution having apredetermined temperature or higher can be maintained in the urea watertank 71, and the reduction in the capacity of the exhaust gaspurification of the second case 29 can be prevented in cold districtsand the like. The water-feeding port 72 of the urea water tank 71 can beadjacently arranged on the operator's boarding and alighting portion ofthe operating cabin 57, and water-feeding work of the urea aqueoussolution into the urea water tank 71 can be easily executed at theoperator's boarding and alighting sites, and the workability ofreplenishing the urea aqueous solution for the exhaust gas purificationcan be improved.

As illustrated in FIGS. 1 to 12, and 17, regarding the engine device forthe work vehicle that includes the first case 28 that removes theparticulate matter in the exhaust gas of the diesel engine 1 and thesecond case 29 that removes the nitrogen oxides in the exhaust gas ofthe diesel engine 1 and connects the first case 28 to the second case 29via the urea mixing pipe 39, the engine device includes the plurality ofcase fixing bodies 95 and 96 for adhering to the first case 28 and thesecond case 29 and the supporting frame bodies 98 for adhering to theplurality of case fixing bodies 95 and 96, and the case fixing bodies 95and 96 and the supporting frame bodies 98 are coupled in such a mannerthat the mounting angle (mounting position) can be adjusted, and theposture of the exhaust gas inlet portion 34 of the first case 28 isconfigured to be capable of adjusting with respect to the mountingsurface of the diesel engine 1, so that when the first case 28 and thesecond case 29 are assembled into the diesel engine 1 as a single unit,the mounting angles of the case fixing bodies 95 and 96 and thesupporting frame bodies 98 are adjusted, and the coupling surface of theDPF inlet pipe 34 as the exhaust gas inlet portion of the first case 28can be easily joined with the exhaust gas outlet surface 7 a of thediesel engine 1. The mounting positioning work of the first case 28 andthe second case 29 can be simplified. That is, the attachable anddetachable workability of the first case 28 and the second case 29 canbe improved, and the assembly work or the maintenance work of the dieselengine 1 can be easily simplified.

As illustrated in FIGS. 1 to 12, the exhaust gas purification device 27as the exhaust purification unit is formed with the cases 28 and 29, thecase fixing bodies 95 and 96, and the supporting frame bodies 98, andthe lower end sides of the plurality of supporting leg bodies 82, 84,and 86 are adhered to the outer side surface of the cylinder head 2 ofthe diesel engine 1, and the supporting frame bodies 98 are coupled withthe upper end sides of the plurality of supporting leg bodies 82, 84,and 86. Accordingly, the maintenance work on the upper surface side ofthe diesel engine 1 and the like can be easily executed through theattachment or detachment of the exhaust gas purification device 27. Thesupporting frame bodies 98 are firmly coupled with the cylinder head 2via the plurality of supporting leg bodies 82, 84, and 86, and while theexhaust gas purification device 27 can be supported with high rigidityon the upper surface side of the diesel engine 1 and the like,interference with the accessory components of the diesel engine 1 can beeasily reduced.

As illustrated in FIGS. 1 to 12, the supporting stand 87 is arrangedapproximately horizontally on the upper surface side of the dieselengine 1 via the plurality of supporting leg bodies 82, 84, and 86, andthe supporting frame bodies 98 are adhered on the upper surface side ofthe supporting stand 87. Accordingly, during the maintenance work orrepair work of the diesel engine 1, the first case 28 and the secondcase 29 can be easily detached from the diesel engine 1, and themaintenance work and the like on the upper surface side of the dieselengine 1 can be simplified.

As illustrated in FIGS. 1 to 12, and 15, it is configured that part ofthe lower surface side of the supporting stand 87 is brought in surfacecontact with part of the exhaust gas outlet surface 7 a of the dieselengine 1, and the supporting stand 87 is fixed on the diesel engine 1 ina horizontal posture with the exhaust gas outlet surface 7 a of thediesel engine 1 as a reference. Accordingly, the supporting stand 87having high rigidity structure can be constituted with low costs bymeans of sheet metal processing, and the positioning work at the time ofassembly, in which the supporting frame bodies 98 are assembled on theupper surface side of the supporting stand 87, can be easily simplified,and the supporting stand 87 can be easily coupled with the diesel engine1 in a predetermined supporting posture.

Subsequently, as illustrated in FIGS. 1, 2, and 5, in the interior ofthe first case 28, the differential pressure sensor 111 for detecting adifference between the exhaust gas pressure on the exhaust gas intakeside (upstream side) and the exhaust gas pressure on the exhaust gasdischarge side (downstream side) of the soot filter 31 is included. Oneend side of the sensor bracket 112 is fastened with bolts to the SCRinlet-side flange body 40, and the other end side of the sensor bracket112 is provided in such a manner as to protrude from the SCR inlet-sideflange body 40 to the upper surface side of the first case 28, and thedifferential pressure sensor 111 is adhered to the other end side of thesensor bracket 112. The differential pressure sensor 111 is arranged onthe upper lateral section of the first case 28 via the sensor bracket112. It is noted that one end sides of an upstream-side sensor pipe 113and a downstream-side sensor pipe 114, each of which is made ofsynthetic rubber, are respectively connected to the differentialpressure sensor 11. In the first case 28, the other end sides of theupstream-side sensor pipe 113 and the downstream-side sensor pipe 114are respectively connected to the upstream side and downstream side ofthe soot filter 31.

Also, an upstream-side gas temperature sensor 115 for detecting anexhaust temperature on the exhaust gas intake side of the dieseloxidation catalyst 30, and a downstream-side gas temperature sensor 116for detecting an exhaust temperature on the exhaust gas discharge sideof the diesel oxidation catalyst 30 are included, and a difference(differential pressure of exhaust gas pressure) between exhaust gaspressure on the inflow side of the soot filter 31 and exhaust gaspressure on the outflow side of the soot filter 31 is detected by thedifferential pressure sensor 111, and an exhaust gas temperature of thediesel oxidation catalyst 30 portion on the exhaust gas intake side ofthe soot filter 31 is detected by each of sensors 115 and 116. That is,the residual amount of particulate matter in the exhaust gas captured bythe soot filter 31 is proportional to the differential pressure of theexhaust gas, and therefore, when the amount of particulate matterremaining in the soot filter 31 increases to a predetermined amount ormore, soot filter regeneration control (for example, fuel injectioncontrol or intake control of the diesel engine 1 wherein the exhaust gastemperature is raised), in which the amount of particulate matter in thesoot filter 31 is reduced, is executed based on the detection results ofthe differential pressure sensor 111.

Subsequently, the assembly and disassembly structure of the first case28 will be described referring to FIGS. 18 and 19. As illustrated inFIGS. 18 and 19, the first case 28 is formed of an exhaust intake sidecase 121 in which the DPF inlet pipe 34 is provided, and an exhaustdischarge side case 122 in which the DPF outlet pipe 35 is provided. Itis configured that the oxidation catalyst 30 is internally installed inthe exhaust intake side case 121, and the soot filter 31 is internallyinstalled in an inner tube 122 b of the exhaust discharge side case 122,and the exhaust gas intake side of the inner tube 122 b is internallyinstalled in an outer tube 122 c of the exhaust discharge side case 122,and the exhaust gas discharge side of the inner tube 122 b is protrudedfrom the outer tube 122 c.

Also, the exhaust gas discharge side of the inner tube 122 b is insertedinto the exhaust intake side case 121 in an insertable and extractablemanner, and a case flange body 121 a of the exhaust intake side case 121and a case flange body 122 a of the outer tube 122 c are fastened withbolts 123 in a separable manner, and the exhaust intake side case 121and the exhaust discharge side case 122 are coupled with each other in adetachable manner. In contrast, the DPF outlet pipe 35 as an exhaustoutlet pipe is provided in the exhaust discharge side case 122 (theouter tube 122 c), and the exhaust gas outlet side of the DPF outletpipe 35 is extended in the radial direction (the direction intersectingwith the cylindrical axial line of the first case 28) intersecting withthe transfer direction of the exhaust gas in the first case 28.Furthermore, the DPF outlet-side flange body 41 for coupling the ureamixing pipe 39 with the DPF outlet pipe 35 is formed of an outlet pipeflange 41 a of the exhaust gas outlet-side end portion of the DPF outletpipe 35 and a mixing pipe flange 41 b of the exhaust gas inlet-side endportion of the urea mixing pipe 39, and the outlet pipe flange 41 a ispositioned on the outer lateral section of the cylindrical outercircumferential surface of the exhaust discharge side case 122 (theouter tube 122 c).

That is, on the outside of the exhaust discharge side case 122, the DPFoutlet pipe 35 is extended on the outside in the direction intersectingwith the transfer direction of the exhaust gas, and the coupling portion(the DPF outlet-side flange body 41) of the urea mixing pipe 39 and theDPF outlet pipe 35 is disposed at a position deviated from theseparation locus of the exhaust discharge side case 122, separated inthe transfer direction of the exhaust gas. It is configured that themixing pipe flange 41 b is fastened with bolts 124 to the outlet pipeflange 41 a, and one end side of the urea mixing pipe 39 is coupled withthe DPF outlet pipe 35, and the other end side of the urea mixing pipe39 is coupled with the SCR inlet pipe 36 via the SCR inlet-side flangebody 40, and the DPF outlet pipe 35, the urea mixing pipe 39, and theSCR inlet pipe 36 are integrally fixed.

With the aforementioned constitution, when the residual amount (thedetection values of the differential pressure sensor 111 and the like)of particulate matter in the soot filter 31 increases to or over a rangewhere the regeneration control can be performed, the bolts 123 areremoved, and the fastening of the case flange bodies 121 a and 122 a isreleased, and when the bolts 124 are removed, and the fastening of theoutlet pipe flange 41 a and the mixing pipe flange 41 b is released, theexhaust discharge side case 122 can be separated from the exhaust intakeside case 121. The exhaust discharge side case 122 is alienated from theexhaust intake side case 121 in the direction of the cylindrical axialline of the first case 28 (the transfer direction of the exhaust gas),and the inner tube 122 b is pulled out from the exhaust intake side case121, thereby disassembling the first case 28 in a detachable manner.Next, the maintenance work of the first case 28, in which the sootfilter 31 is taken out from the inner tube 122 b, and the particulatematter in the soot filter 31 is artificially removed, is carried out.

It is noted that when the bolts 123 are removed, and the fastening ofthe case flange bodies 121 a and 122 a is released, the exhaust intakeside case 121 is supported by the exhaust gas outlet pipe 7 via the DPFinlet pipe 34, and when the bolts 124 are removed, and the fastening ofthe outlet pipe flange 41 a and the mixing pipe flange 41 b is released,the urea mixing pipe 39 is supported by the second case 29 via the SCRinlet-side flange body 40. Accordingly, in the maintenance (filterregeneration) work of the soot filter 31, it is only necessary to removethe exhaust discharge side case 122, but it is not required to removethe exhaust intake side case 121 or the urea mixing pipe 39, so that themaintenance man-hour of the soot filter 31 can be reduced, compared withthe structure required for the disassembly of the exhaust intake sidecase 121 or the urea mixing pipe 39.

As illustrated in FIGS. 1 to 7, 18, and 19, regarding the engine devicefor the work vehicle that includes the first case 28 that removes theparticulate matter in the exhaust gas of the engine 1 and the secondcase 29 that removes the nitrogen oxides in the exhaust gas of theengine 1 and connects the first case 28 to the second case 29 via theurea mixing pipe, the first case 28 is formed in such a manner as to bedivided into the exhaust intake side case 121 and the exhaust dischargeside case 122, and the exhaust discharge side case 122 is configured tobe separable in a state where the exhaust intake side case 121 issupported on the side of the engine 1. Accordingly, during themaintenance work in the interior of the first case 28, it is notrequired to remove the whole of the first case 28, and the number ofdetachable components that necessitate the maintenance work in theinterior of the exhaust discharge side case 122 (the first case) can beeasily reduced, and the soot filter 31 internally installed in theexhaust discharge side case 122 and the like can be easily detached, andthe cleaning man-hour of the interior of the exhaust discharge side case122 or the soot filter 31, or the like can be reduced.

As illustrated in FIGS. 1 to 7, 18, and 19, the DPF outlet pipe 35 as anexhaust outlet pipe that connects the urea mixing pipe 39 to the firstcase 28 is included, and on the outside of the exhaust discharge sidecase 122, the DPF outlet pipe 35 is extended on the outside in thedirection intersecting with the transfer direction of the exhaust gas,and the coupling portion (the DPF outlet-side flange body 41) of theurea mixing pipe 39 and the DPF outlet pipe 35 is disposed at a positiondeviated from the separation locus of the exhaust discharge side case122, which is separated in the transfer direction of the exhaust gas.Accordingly, the fastening bolts of the coupling portion of the ureamixing pipe 39 and the DPF outlet pipe 35, or the like are detached, andthe coupling of the exhaust intake side case 121 and the exhaustdischarge side case 122 is released, so that the exhaust discharge sidecase 122 is slid in the transfer direction of the exhaust gas in thefirst case 28, thereby easily separating the exhaust discharge side case122 from the exhaust intake side case 121.

As illustrated in FIGS. 1 to 7, 18, and 19, it is configured to includethe case fixing bodies 95 and 96 and the fastening bands 97, as aclamping means, for adhering to the exhaust intake side case 121 and thesecond case 29, and the case fixing bodies 95 and 96 and the fasteningbands 97, as a clamping means, for adhering to the exhaust dischargeside case 122 and the second case 29, and the first case 28 and thesecond case 29 are integrally adhered by means of the case fixing bodies95 and 96 and the fastening bands 97, thereby forming the exhaust gaspurification device 27 as the exhaust purification unit. Accordingly,the exhaust discharge side case 122 can be easily detached by removingthe fastening bands 97 that fasten the exhaust discharge side case 122and the second case 29. During the maintenance of the interior of theexhaust discharge side case 122, the attachment or detachment work ofthe fastening band 97 that fastens the exhaust intake side case 121 andthe second case 29 is eliminated, so that maintenance (the cleaning ofthe soot filter) workability in the interior of the exhaust dischargeside case 122 can be improved.

As illustrated in FIGS. 1, and 9 to 12, it is configured to include thecase fixing bodies 95 and 96 and the fastening bands 97 with which thefirst case 28 and the second case 29 are integrally adhered, and thesupporting stand 87 for mounting the case fixing bodies 95 and 96, andthe plurality of supporting leg bodies 82, 84 and 86 are verticallyinstalled on the upper surface side of the diesel engine 1, and thesupporting stand 87 is coupled with the exhaust manifold 6 of the dieselengine 1 and the plurality of supporting leg bodies 82, 84 and 86.Accordingly, the machining errors of the mounting components such as thesupporting stand 87 can be alleviated by adjusting the coupling portionsbetween the supporting leg bodies 82, 84, and 86 and the supportingstand 87, and an inclination angle in mounting the supporting stand 87can be easily corrected, and the first case 28 and the second case 29can be easily supported in a predetermined posture, and the supportingstand 87 is separated away from the accessory components of the dieselengine 1, thereby supporting the first case 28 and the second case 29 insuch a manner as to eliminate mutual interference. The assemblyworkability, in which the first case 28 and the second case 29 areassembled into the diesel engine 1, can be easily improved.

Next, a skid-steer loader 151 in which the diesel engine 1 is mountedwill be described referring to FIGS. 20 and 21. The skid-steer loader151 as the work vehicle illustrated in FIGS. 20 and 21 is configured tobe equipped with a loader device 152 described later and perform loadingwork. The skid-steer loader 151 is equipped with right and lefttravelling crawlers 154. Also, a hood 155 that is openable and closableis arranged above the travelling crawlers 154 of the skid-steer loader151. The diesel engine 1 is stored in the hood 155. In the interior ofthe hood 155, the first case 28 and the second case 29 are placed andfixed on the upper surface portion of the diesel engine 1.

The diesel engine 1 is supported by a travelling vehicle body 156included in the skid-steer loader 151 via a vibration-proof member andthe like. A cabin 157 in which an operator gets on is arranged in frontof the hood 155, and a maneuvering handle 158, an operating seat 159,and the like are provided in the interior of the cabin 157. Also, aloading work hydraulic pressure pump device 160 that is driven by thediesel engine 1 and a travelling mission device 161 for driving theright and left travelling crawlers 154 are provided. The motive powerfrom the diesel engine 1 is transmitted to the right and left travellingcrawlers 154 via the travelling mission device 161. An operator whotakes the operating seat 159 can perform the driving operation of theskid-steer loader 151 and the like via an operating portion such as themaneuvering handle 158.

Also, the loader device 152 includes loader posts 162 arranged on bothsides of the right and left of the travelling vehicle body 156, a pairof right and left lift arms 163 coupled with the upper end of eachloader post 162 in an oscillatory manner up and down, and buckets 164coupled with the tip end portions of the right and left lift arms 163 inan oscillatory manner up and down.

A lift cylinder 166 for oscillating the lift arm 163 up and down isprovided between each loader post 162 and the corresponding lift arm163. A bucket cylinder 168 for oscillating the bucket 164 up and down isprovided between the right and left lift arms 163 and the buckets 164.In this case, it is configured that the operator on the operating seat159 operates a loader lever (not illustrated), and the hydraulicpressure force of the loading work hydraulic pressure pump device 160 iscontrolled, and the lift cylinders 166 or the bucket cylinders 168operate in a stretchable, contractible manner, and the lift arms 163 orthe buckets 164 are oscillated up and down, thereby executing theloading work. It is noted that the urea water tank 71 is internallyinstalled in the upper portion of the front lateral section of the hood155. Also, the radiator 19 arranged opposite to the cooling fan 24 isinternally installed in the rear portion of the hood 155.

REFERENCE SIGNS LIST

-   1 Diesel engine-   2 Cylinder head-   6 Exhaust manifold-   24 Cooling fan-   28 First case-   29 Second case-   34 DPF inlet pipe-   39 Urea mixing pipe-   56 Hood-   57 Cabin-   71 Urea water tank-   82 Front portion supporting leg body-   84 Lateral portion supporting leg body-   86 Rear portion supporting leg body-   87 Supporting stand

The invention claimed is:
 1. An engine device for a work vehicle, theengine device comprising: a first case configured to remove particulatematter in an exhaust gas of an engine, a second case for removingnitrogen oxides in the exhaust gas of the engine, and a urea mixing pipeconfigured to connect the first case to the second case, wherein thefirst case and the second case are integrally attached by case fixingbodies, fastening bands, and supporting frame bodies to form an exhaustgas purification unit, and wherein a plurality of supporting leg bodiesare vertically installed in a cylinder head of the engine, and asupporting stand is coupled on an upper end side of the first pluralityof supporting leg bodies, and the supporting stand is attached to anupper surface side of the engine in an approximately horizontal state,and the case fixing bodies are attached to an upper surface side of thesupporting stand via the supporting frame bodies, and wherein theengine, the first case, and the second case are configured to beintegrally vibrated in a swingable manner, wherein an inlet pipe of thefirst case is arranged on a side where an exhaust manifold of the engineis installed, and wherein the second case is juxtaposed on a lateralpart of the first case on an installation side of a cooling fan of theengine, and wherein the urea mixing pipe is supported between the firstcase and the second case on an upper surface side of the first andsecond cases.
 2. The engine device for the work vehicle according toclaim 1, wherein the work vehicle comprises an operating cabin arrangedin a rear of a hood in which the engine is internally installed, andwherein a urea water tank for exhaust gas purification is installedbetween a front portion of the operating cabin and a rear portion of theengine.
 3. The engine device for the work vehicle according to claim 1,wherein the first case is divided into an exhaust intake side case andan exhaust discharge side case, and the exhaust discharge side case isconfigured to be separable in a state where the exhaust intake side caseis supported on the engine side.
 4. The engine device for the workvehicle according to claim 3, further comprising an exhaust outlet pipeconfigured to couple the first case with the urea mixing pipe, andwherein the exhaust outlet pipe is extended on an outer side in adirection intersecting with a transfer direction of the exhaust gas, onan outer side of the exhaust discharge side case, and wherein a couplingportion between the urea mixing pipe and the exhaust outlet pipe isdisposed at a position deviated from a separation locus of the exhaustdischarge side case separated in the transfer direction of the exhaustgas.
 5. The engine device for the work vehicle according to claim 3,further comprising a first clamping body for adhering the exhaust intakeside case and the second case; and a second clamping body for adheringthe exhaust discharge side case and the second case, and wherein thefirst case and the second case are integrally attached with eachclamping body, thereby forming an exhaust purification unit.
 6. Theengine device for a work vehicle according to claim 1, wherein theplurality of supporting leg bodies comprises three leg bodies.
 7. Theengine device for a work vehicle according to claim 1, wherein theplurality of supporting leg bodies comprises a front portion supportingleg body, a lateral portion supporting leg body, and a rear portionsupporting leg body.
 8. The engine device for a work vehicle accordingto claim 1, wherein each of the plurality of supporting leg bodiesextends longitudinally in a direction from the cylinder head to thesupporting stand.
 9. The engine device for a work vehicle according toclaim 1, wherein a first of the fastening bands is operably connected tothe first case and a second of the fastening bands is operably connectedto the second case, and wherein each fastening band is operablyconnected to one of the case fixing bodies.
 10. The engine device for awork vehicle according to claim 1, wherein the first case is mounted insuch a manner that the exhaust gas in the first case can transfer in adirection intersecting with a longitudinal axis of an output shaft ofthe engine.